1. Field of the Invention
The present invention is directed to a distributed switching system, such as, for example, a multiservice switching system based on, for example, frame, cell or packet switching, that supports video, private line and data services.
2. Discussion of Background and Related Information
A multiservice switching system (MSS) includes a distributed switching device designed to support multiple forms of data, such as, for example, voice, computer data, digital data and video signals. Switching can be based on, for example, frame, cell or packet switching. Multiservice switching systems may use a broad range of access technologies, including, for example, time division multiplexing (TDM), digital subscriber lines (xDSL), wireless, and cable modems.
For example, in an asynchronous transfer mode (ATM) switched virtual circuit (SVC) service, an SVC customer can either initiate or terminate an SVC service request via a user-to-network (UNI) interface. The SVC customer may be, but is not limited to, for example, an individual subscriber, an enterprise network, an Internet service provider (ISP), or a peer network. Service policies define the capabilities and resources available to the customer. The service policies also determine whether a service request succeeds or fails.
The amount of data being transmitted between locations has rapidly escalated. Voice networks (e.g., traditional telephone networks) are becoming overwhelmed by the rapidly increasing traffic flow. Further, it is costly to construct/expand such traditional telephone networks. As a result, companies are searching for ways to carry voice services over packet networks, and for removing data traffic from the voice networks. This has led to the development of media gateways and media gateway controllers (referred to as distributed switches) that separate the service intelligence from the associated hardware, and allows voice and data to be carried over a packet network.
Conventional architectures do not permit the separation of a service controller from a transport controller. For example, in a conventional ATM switch, a calling party uses the UNI protocol to request an ATM SVC connection to another end system that is connected to the network. This request is carried by a signaling channel to an ATM edge switch, which terminates the UNI protocol and initiates a private network-network interface (PNNI) protocol to complete a setup across the network to the edge switch that connects to the called party. The application of policy and the decision to reject or accept a call is determined solely by an on-board processor within the switch. That is, service control is packaged into the switch. No standardized mechanism currently exists to utilize service control outside of the switch or other transport controller.